A Multiservice Access Concentrator (MAC) provides traffic shaping by allocating at least one cell stream to at least one cell slot of a cell scheduling table. A cell slot and a corresponding cell stream are designated in response to a cell interrupt signal generated following cell transmission. At least one counter and at least one credit buffer are maintained, and a service class of the designated cell stream is determined. The size of the credit buffer is determined by a maximum burst cell size (MBC) of the corresponding cell stream and virtual circuit (VC). A cell of the designated cell stream is transmitted in response to the determined service class and a count of the at least one counter and contents of the at least one credit buffer. Therefore, cells are transmitted based on cell credits. A virtual circuit (VC) builds cell credit based on the sustained cell rate (SCR) of the VC. Cell credit is consumed as cells are transmitted. If no data is queued or transmitted, the cell credit builds to a maximum burst cell size (MBC). When data is queued again and credit is available, cell transmissions may burst to the peak cell rate (PCR) until credit is exhausted. Cell transmission timing is controlled using the cell interrupt signal, wherein the cell interrupt signal emulates a clock signal.